Six different energy-saving treatments for large window areas were tested by Tompkins-Cortland Community College (TCCC) to coordinate energy saving with building design. The TCCC building has an open space design with 33,000 square feet of external glass and other features causing heating problems and high energy costs. Phase I of the window-treatment study, initiated in 1977, reviewed traditional and innovative conservation strategies and methods of measuring window treatment effectiveness. Six available window treatments were installed and tested (i.e., Plexiglas, 3M P-19 reflective film, Seco Thermoshade, thermofold drapes, Tuffak-Twinwall, and GE Lexan Sheet). Test areas were selected on the basis of the suitability of the treatment to the location, ability of testers to examine effects of the treatment, and preferences of people using the space. Concurrent with Phase I, TCCC prepared a curriculum in energy conservation, making it possible for work-study students to record field data such as temperatures and wind speed. Additionally, TCCC contracted for a mobile thermograph and monitored interior temperatures and heat flow. The six treatments were evaluated in terms of heat flow reduction, maintenance problems, delivery and installation time, cost, and acoustic, visual, and aesthetic concerns. In Phase II, insulating draperies were selected for windows in high traffic areas, and Seco Thermoshades and Plexiglas sheets were selected for low-use, difficult access areas. Tables, graphs, and technical appendices constitute the bulk of the report. (KL)